I want to ask about the inversion used for short responses in conversations:


- I heard about them.

- So did I. (= I heard about them too.)

How can I use the inversion in this context:

- They both affected you badly.

- So …… (= they both affected you too)
- They both affected you badly.
- And you, too.

('So did they you' is so formal that it is antiquated.)
Students: We have free audio pronunciation exercises.
Thank you, Mister Micawber

I just want to clarify two things:

1) From your variant of response “and you, too”, is it clear what was meant here? Because I can see two variants of interpretation

And you, too = they both affected you too

= you affected me too.

2) Is this variant of inversion ('So did they you') never used or can be used in some situations? (formal conversations for example)
1-- There is no confusion; you must allow for common sense.
2-- Never used in this century, to the best of my knowledge... if a short reponse could ever be considered 'formal'.